Do you know WHY we have a turbulence penetration speed? Do you understand what it is for?
Hint: The turbulence penetration speed has NOTHING to do with PASSENGER COMFORT.
The passengers pay your wages.
Turbulence is to be avoided where possible, not exacerbated by accelerating in it.
Weather radar does not display small CU. it displays CBs. However I have a pair of eyes, and I look out the window. When I see CU ahead of me I will ask for a deviation. Sometimes I get it in time, on other occasions I won't. HK is busy and constrained airspace. More often than not I'm just forced to plow through stuff. Small CU can be very rough. Even a layer of ST can cause significant bumping around. I'd be a fool to accelerate in that.
Likewise at night, if my lights show I'm entering cloud, and can't tell what it is, or what might be embedded in it, I do not want to accelerate to 290kts, and I will not do so.
Thank you.